The final goal is to complement, integrate and extend with a quantitative characterization of the bulk flow the description currently adopted to classify altered hemodynamics, which is based on wall shear stress (WSS).
Hemodynamic simulations of two image-based carotid bifurcation geometries were carried out assuming a reference Newtonian viscosity, two non-Newtonian rheology models and Newtonian viscosities based on characteristic shear rates. WSS-based and Lagrangian-based metrics for helical flow quantification and for vorticity dynamics quantification were calculated.
Our findings suggest that the assumption of Newtonian rheology: (1) could be reasonable for bulk flow metrics (differences from non-Newtonian behavior are lower than 10 % ); (2) influences at different levels the WSS-based indicators, depending on the bifurcation model, even if in our study it is lower than the major source of uncertainty as recognized by the literature (i.e., uncertainty on geometry reconstruction).